Definitions for "Extrados"
Keywords:  voussoirs, arch, intrados, vault, curve
The exterior curve of an arch; esp., the upper curved face of the whole body of voussoirs. See Intrados.
The convex curve of a masonry arch. The upper surface of the voussoirs when in position.
The outside line of an Arch
Keywords:  backwall, bend, arc, outside, see
The outside arc of the bend (see Backwall).